总剂量效应对CMOS图像传感器中光电二极管钳位电压的影响  

Influence of TID Effect on Pinning Voltage of CIS

作　　者：宋辰昱 申人升[1] 曲杨 刘岩[1] 常玉春[1] SONG Chenyu;SHEN Rensheng;QU Yang;LIU Yan;CHANG Yuchun(School of Microelectronics,Dalian University of Technology,Dalian 116600,CHN)

机构地区：[1]大连理工大学微电子学院,辽宁大连116600

出　　处：《半导体光电》2021年第3期321-326,共6页Semiconductor Optoelectronics

基　　金：国家自然科学基金项目(11975066);工业和信息化部电子第五研究所项目基金项目(JSZL3017610B001)。

摘　　要：钳位电压(V_(pin))是影响CMOS图像传感器(CIS)中钳位光电二极管(PPD)电荷转移效率和满阱电荷容量的关键物理量。在辐照条件下,V_(pin)受辐射总剂量(TID)增加而升高,因此研究其机理对抗辐照CIS的设计有重要意义。文章利用TCAD仿真软件分析了CIS器件的电学特性,研究了V_(pin)受TID影响的机理。结果表明,当辐照引起的氧化物陷阱电荷浓度达到3×10^(16)cm^(-3)时,浅沟槽隔离(STI)附近的耗尽区将PPD中的pin层与地极电学隔离,从而导致pin层电势易受到传输晶体管TG沟道电势影响而增加,使得相同电子注入条件下PPD可存储的电子增多,复位所需电压增大,导致V_(pin)随着辐射总剂量增加而增大。Pinning voltage(V_(pin))is the key parameter affecting the charge transfer efficiency and full well capacity of the pinned photodiode(PPD)in CMOS image sensor(CIS).Experimental results show that V_(pin)increases with the total radiation dose(TID)effect,so it is of great significance to study the reasons in the design of anti-irradiation CIS.In this paper,TCAD simulation software is employed to analyze the electrical characteristics of the CIS and study the mechanism of V_(pin)affected by TID.The results show that when the concentration of trapped charges caused by irradiation reaches 3×10^(16)cm^(-3),the depletion region near the shallow trench isolation(STI)isolates the pin layer of the PPD from ground,which causes the potential of the pin layer to be easily affected by the transfer transistor channel to increase.Thus under the same electron injection,the number of electrons stored in the PPD increases and the reset voltage needs to be higher,and V_(pin)increases with the increases of TID.

关 键 词：钳位电压 总剂量效应 CMOS图像传感器 TCAD 

分 类 号：TN406[电子电信—微电子学与固体电子学]